摘要
采用改进熔盐法经一步反应合成了直径50-80nm,长度为1-5μm的单晶PbTiO3纳米棒。纳米棒沿(100)晶向生长,其形成可以用Ostwald成熟机制来解释。PbTiO3纳米棒晶格结构为四方(a=b=3.926,c=3.963),与单晶相比四方性明显下降。通过变温拉曼测试发现其铁电-顺电相变温度为440℃,低于单晶(490℃)。相变过程中“软模”E(1TO)的软化行为(从67 cm-1到56 cm-1)比单晶显著减弱,表明钛酸铅纳米棒中铁电性的弱化。
： We synthesized single - crystalline PbTiO3 nanorods with diameter of 50 - 80 nm and length of 1 - 5 μm through a one - step reaction in NaCl flux. The growth of the nanorods can be explained by the Ostwald ripening mechanism. The nanorods were in tetragonal structure with lattice parameters of a = 3. 926A and c = 3. 963A, respectively. Temperature dependence of Raman spectra shows that the ferro - papaelectric transition temperature of the PbTiO3 nanorods is 440℃, lower than 490℃ for bulk crystals. A weaker softening behavior of the E（1TO） soft mode has been observed in PbTiO3 nanorods （from 67 cm^-1 to 56 cm^-1） than that in crystals （from 82 cm^-1 to 45 cm^-1）, showing weakening of ferroelectricity.
出处
《光散射学报》
2006年第1期5-9,共5页
The Journal of Light Scattering
基金
国家自然科学基金资助项目(No.10374047&No.10174034)
关键词
钛酸铅单晶纳米棒
生长机制
声子特性
single- crystalline PbTiO3 nanorod
growth mechanism
phonon characters
